Fire-protection-signal system.



J. G. NOLEN & J. E. SHEPHERD FIRE PROTECTION SIGNAL SYSTEM.

APPLIUATION FILED MAR. 20, 1905.

Patented Feb. 23, 1909.

2 BHEBTSSHEET 1.

J. G. NOLEN & J. E. SHEPHERD.

FIRE PROTECTION SIGNAL SYSTEM. APPLICATION FILDED MAR. 20, 1905.

91 3,041 Patented Feb. 23, 1909.

2 SHEETS-SHEET 2.

T v \D A: 50 d ZV cZmea-acw lnaemr s I 0mg; JOZsva dieyoerd UNITED .sTAT ss ATENT oFi roE.

JAMES e. NOLEN AND JOHN SHEPHERD, or GHIGAGQQILLINOIS; SAI'D NOLEN ASSIGNOR TO-SAID SHEPHERD.

FIRE-PRQTECTION-SIGNAL SYSTEM.

Application filed March 20, 1905. Serial No.250,956.

Specification of Letters Patent.

Pz tented Feb. 23, 1909 To all whom it may concern:

Be it known'thzit we, JAMES G. NOLEN and JOHN E. Si iEPHERD,'of Chicago, in ie county of Cook and State of Illinois, have invented certain new, and 'useful Improvements into provide an electric signaling system, operatiiig in conjunction. with devices of on autometi'c sprinkler systein,in.suchnienner that the continued presence for a definite tiine' 'of.

a predetermined condition, such tS '\Vfl.t(l flow. in the sprinklersysteni, will occasion the transmission to 8. central or other supervisory station of an alarm; whilc ii momentary existence of said condition, such as not to require attention of the supervisory -a.'utl i.or ities, does-not transmiten elm-n1.

Afurther'objectof our invention is to pro- Vide-betweendevicesinteriorly locetedjin :1

devices of 1 the system exterior-iv lo sled relative tosaid-receptacle, such connection as willseoure the proper correlation of action of the sprinkler and signal system without -subthe sprinkler systenr to the danger pcrage, the connection maintaining A manently the hermetic closure of the extinguish'er receptacle. 1

"A further object of our invention is to pro- -vide improved appliances for sprinkler supervisory systems, and

connections for'such appliances, whereby edvantages .fere attained which ni:i v hcst be understood from vthe iollowipg description taken inconjunction drawings, wherein: p

Figure -1 18 it. dmgremnuiticrepresent at ion with the eccoiiipsiiyii g of portions, of ziyiire protection system.

equipped in eccoi'dencewith;our inventio Fig. fl is a side elevation of :i portion ol the ap})8,l t1lS, tT.-\l, Fig. 3 is a. top 'plz n view of the instrun'ientelity shown in Fig. 2. Figs. 4,i5',fsnd'6 are diagramsshowing the action of the-time switch. t4 rcprcsent conventionally the tr Fig. 9 modification of a portion of Fig. 1. I

'llirou'ghout the drawings like innnciz-rls and letters oi .rcicrcr-cc rcler always to like parts instrumentiilities improved circuit.

Referring now to the diagrammatic view, Fig. 1, 10 indicates e riser of a ire-extinguishcr system, as typifying an element wherein fluid flows when thesystem is active,

and containing a iiiova'ble'pert such as a valve .11, normally occupying sigiveii posi operation, and occupying another position when the system s active-01 in operetion. In the specific embodiment llustrated, 11

.'tion when the system is passive; or-out of indicates evolve, locaitedin the pipeor riser 10, end srrsngedfundernorrrnil condition to rest upon its seat 12 within the-valve casing '13. From the valve 11 connection is established with devices forming "part ofthe alarm or signal system, arriinged ex terio-rly to the casing ,13,.such connection being preferably established through the heroin shown, hermetic closing of the receptacle at Ia'll wlierebv times is insured. As to some features 'ofour invention,

how ever,. such .COIlnechiQn'. i IIOt'QSSQIItIiLl. r

' Specifically l lindiciitesa tubular bushing threaded into'nv suitable opening in the valve casing 13, and having secured across it e tightdiztphragni 15, held in plaice suitable incznis such as. the zinnularfcep Associated with said diaphragm 15th fu cruni thcrcin is H lever 17, preferably inthe form of a red or stem, suitably. secured with a. hermetic joint to the diaphragm ]5 centrallythereof, and extending \Yltliill and \VltllOUtthc velvc cnsiiig thro'ughsuid diaphragm. lhc inner end, T17, of said stem, is associated with the valve. 1'] 'for control by said viilvc. the arrangement ofipm'ts being the valve 11.

.l lrtcriorlv of thc ("using we associate the cud 17 of thc stcni or lcvcr 17. with :i switch. or other .cnicuitwiii'yiiig dcvicc 'r'orrninc; part of an .clcctric signal or alarm .systcni, zll tl' so arrange the devices that when the end 17 of the lever is lowered the switch is actuated tovery the conditions 0t having two enlarged portions or chambers adapted to condition the devices of the electric circuit, wherein it is associated, for operation only upon the .maintenance of the movable. element of the fire extinguisher system in condition showing activity of said system during a predetermined time, thereby avoiding the transmission of signals or the sounding of al'arms at every momentary occurrence of movement of said movable members of said fire extinguisher system to position, indicative of activity in the system.

Specifically, 18 indicates in general an electric time switch suitable for carrying out our invention, and preferably comprising essentially a movable receptacle 19 20, 20, connected by a restricted passage or" duct 20", said receptacle including a movable body, preferably of mobile, elec trically conductive liquid, such as mercury, adapted, when the chamber is moved, to shift from one enlargement thereof to the other, the movementof said mobile liquid being adapted to influence a circuit, or circuits, having terminals in the receptacle.

We prefer that the receptacle 19 be mounted in 2. containing carrier 21., pivotally supported as at" 22 in a suitable frame 23 in such manner that one end of the carrier 21 constantly tends to swing downward. The stem, 17 is provided with a yoke 24 straddling the carrier 21, and having slots 25 for engagement with the studs 26 secured on said pivoted carrier in front of its pivots. The connections are made in such manner that when the stem is in normal position with its end 17, weighted down by the valve 1.1, the front end of carrier 2]. is tilted upward against its constant tendency to drop, to such position that the body of mercury is substantially all contained in the chamber 20, as shown in Fig. 4, while, when the valve 11 rides the front end of the unbalanced pivoted frame 21 tilts downward so that the chamber 20 is brought below the level of chamber 20, andthe mercury is conditioned to flow from the chamber 20 which it normallyoccupies into the chamber 20, which is normally empty. Such movement of the unbalanced frame 21, depresses the outer end of lever 17 and raises its inner end, the diaphragm 15 serving as a fulcrum for the movetrnent of said lever. The return of the vali'le .11, to

closed position, restores the parts to normal.

positions.

It will be understood, of course, that (the time switch, herein shox'an, is illustrative merely, and that other forms of time switch,

ation, to transmit-a readable or predeter mined plural-impulse signal to a supervisory station, such transmitter or box being herein. diagrannnaticz-rlly illustrated as indicated by the character A. Saidbox A is provided, preferably with two spring motor-driven number heels a and a each adapted to transmit a predetermined signal, distinguishable from the other. The teeth of the two wheels (1 and a are preferably oppositely disposed, that is to saygthe wheels a and a operate in succession in conjunction with their respective contact pens, and each wheel is provided 'cith a body of insulation a adapted and arranged to raise its pen out of contact with the coacting contact pointduring the interval of time "when the teeth of the opposite rihcel are acting upon its pen. Associated v-tith said wheel a, are the pen I) and contact 0 and nith the wheel a the pen Z and contact 0. Both pairs of contact parts being normally closed and being adapted'to be broken by the passage beneath said pens of the teeth of their respective Wheels. The teeth are preferably of such contour as to release the pens for sharp, free return after the passage of the tooth point thereby, so that the pen during each reciprocation caused by the passage of a tooth is momentarily out of contact with both the wheel and its coacting contact part;

A third wheel, a, may be conveniently arranged to constitute part of the box A, and is timed for simultaneous rotation with the "wheels (1. (1,, the v. heel 90 being provided with 'a pen :0 which makes electrical contact in ith the vheel nhile the v. heels 0 a are inactive or in normal position, and which is maintained out of such electrical contact rith heel .1: during the operation of wheels a (1 by a body of insulating material at almost inc-losing v. heel :r.

The PUI'JOSG of the features of construction descri ed n'ill hereafter become apparent.

D indicates in general an electro-res onsive device controlling the operation 0 the number 'iil'lGGlS, said device comprising a magnet, the armature (Z hereof is suitably connected with the clock v. ork of the transmitting box A to control its condition, said magnet being preferably so wound that when all of the normally charged circuits, are en' ergized by current flovi ing in the normal direction its condition is so nearly neutralthat its armature is'unattracted.

The transmitter and magnet arrangement is preferably such that the vheels areconditioned to make one revolution million the magnet armature is moved in either direction, and for a second round, upon the return movement of the armature. This may be accom lished inany suitable v ay, Figs' 7 and-8 i lustrating a simple mechanism \x herein theclockwork is provided a ith the crow n wheel at having two notches a a at different elevations in the flange of the t. heel, and at opposite sides thereof, each notch being adapted for coaction vith a corresponding finger (I or (Z of a yoke (1'' carried by the armature d of magnet D. The cro' n i heel is geared to make one half revolution for each full revolution of the heels a a and r. In operation, the notch a is engaged by finger d when the armature is unattracted, movement of the armature to attracted position releases-wl'ieel a? for a brief revolution until finger dfalls into notch a, the number wheels making a full revolution, and restoration of the armature to tmattracted position at pen Z) of box A.

releasing the heel a for another half revolution until notch a" is again engaged by linger d.

.E indicates in general a central station switch for varying the circuit conditions, F a relay at central station, and G the generator whereby energy is supplied from the central station to the signaling system. The wiring connections of said parts are preferably as follows: The positive pole of generator G is connected with wire'SO, which I will term a main line wire, including at the central station the wiring of relay F and terminating From said pen extend two parallel circuit branches to a point 31, one branch, which for brevity I will hereafter term the supervisory branch, extending from said pen I) by wire 32 to the pen I), from its contact 6 by wire to a coil d of the magnet, D, thence by wire 34, and parallel connections 35, 35, to the two contacts 36, 36' respectively located in chambers 20 and 20 of the time switch receptacle. (orrespondingpontacts 37, 37 are arranged in pairs with the contacts 36, 36 and from them extend parallel wires 38, 38 connected to wire 39 extending to the magnet coil d whose opposite terminal is connected by wire 40 to the point 31. The other branch of the circuit, whi h I will arbitrarily call the main bran 11 extends from said pen I; by its contact 0 and wire 41 through the coils d and d of the magnet D, (which are preferably wo -nd to substantially neutralize the effect of coils d, (F under normal conditions) and thence by wire 42 to the juncture point 3] whence the main circuit continues by wire 43 to the pole 44 of the single-pole, ldoublethrow switc'lt E, the blade e whereof n 'n'mally contacts-with a point 45, connected by wire 46 with ground at the central station. A

Wire 47' also connected with "round ex- I h I tends to the negative pole of the generator G normally completes the circuit through ing contact 48 of the switch E is connectedby wire 49 with the main wirewiO.

The frame work of the transmitter box A, and consequently all of its wheels a ,a/ and 1', are preferably grounded through a suitable ground connection 50. provide, in the normally empty chamber 20 of the time switch, a contact, connected by wire 51 with the pen w of the wheel at, and also a contact connected-by wire 52 with a local battery 53, the other terminal whereof is'connected by wire 54 with a local alarm 55, whence extends a wire 56 establishing connection with another contact in said chamber, preferably by connection with the wire 39.

The armature f, of the relay F at central station, is normally maintained in attracted position, by the magnetof the relay, a d is included in the normally open circuit 57containing the recording instrument, or register, 58, preferably of the ordinary district telegraph messenger-call type, the circuit 57 being closable by movement of the armature f into contact with its back contact 59. The front contact (30 is normally disconnected from circuit- 57, but a switch 61 ispreferably provided, adapted to disconnect contact 59 from, and connect contact to in the circuit 57.

It will now be understood that under normal conditions in the lire extinguisher system, valve 1 1, being closed and the time switch being tilted to such position that the mercury fills the chamber 20 and leaves the chamber 20' substantially empty, the condition of the signaling system will be as follows: Electric current from the generator G traverses line wire 3) and relay 1, (thereby maintaining the armaturef in an attracted position) to the pen I), where the circuit divides, current flowing through both the main, and supervisory branches, to the grounded main line wirc 43, whence connection is made to the negative terminal of the generator by wire 47. The supervisory circuit, it will be ,observed, is closed at the time-switch through the contact of the mercury in chamber 20 with contact points 36 and 37. hen the normal condition in this circuit prevails, it will be understood that the magnet D is balanced and its armature held retracted from the magnet by its spring.

Should now a variation in the conditions in the sprinkler system occur, such as to cause the raising of the valve 11, the unbalanced carrier 21 tilts, lowering the chamber 20 of the time switch, bdlow the chamber 20, thereby conditioning the mercury to flow through the restricted passage 20 into the-cha1nbcr 20. If the opening of the valve 11 be momentary only the flow of mercury tllI'OUglbtllO restricted passa e is not sufficient to break the circuit betw een con tact points 36, 37, and upon the retur irof the valve L1. to normal position and thercstora- We also preferably tion of the carrier 21 to position to raise the chamber above the chamber 20 the mercury flows back into said chamber 20 and no variation in the circuit conditions takes place. If, however, the valve llremains in abnormal or open position for a period of time suilicient to enable enough mercury to flow through the restricted passage to break contact between the terminals 36 and 37, as shown in Fig. 5, and thereby make contact between the terminals36 and 37, as shown in Fig. 6, the following action takes place:

, cuit through contacts 36, 37, however, preferably occurring about the time the insulation a of wheel a is raising pen I), restores the circuit connections, as originally described, and conditions the magnet armature to return to nnattracted position under the influence of its retracting spring, thereby conditioning the box for another round of operation of the number wheels. As a result the box transmits two rounds, each number wheel sending its characteristic number to be received at central station during each revolution. This operation will be well understood by those skilled in the art, as it will be apparent that the two pens and contacts are respectively in the opposite branches of the circuit, and that when the teeth of one number wheel are assing below its corresponding pen the paral e1 circuit connection through the pens of the opposite wheel are broken by the elevation of the pen of said opposite wheel by the insulated pe-' ripheral portion of the wheel coextensive with the toothed portion ofthe then-sending wheel. It will be apparent further that when the wheels are in operation upon the passage of a tooth of either wheel beneath its pen the main circuit is broken through both its parallel branches at the pens, momentarily grounded through one branch by wire 50 and then brokencompletely as the sending pen drops from the wheel teeth, so that register 58 records on the grounding action of each tooth by a break in its dash or rundown, when the wheel a is transmitting, and on the breaking action of each tooth, by a (lot on the tape, when wheel a is transmit ting.

Obviously when the valve 11 reseats-itself, restoring the parts 'to initial position, the operation described will be repeated, circuit being first broken between contact points 36, 3 7, and then made between contacts 36 and 37. In this way the central oflice is notified both of the maintenance of the valve 11 in open position, for a definite length of time, and of its subsequent closing for a similar length of time.

We also prefer that the local circuit, including the gong 55, be provided, it being obvious that when the valve is allowed to remain open for a short time the contact is made between the terminals of the local circuit in the chamber 20 and the gong started in operation to sound until the circuit is broken by the restoration of the time switch to normal condition. y

We prefer also that the ground connections of the time switch and the transmitting box be provided to guard against failure of the system through the breaking of one of the line wires between the central station and the protected area. The central station connections shown are well known to those skilled in the art, and it is customary in systems h'avare connected with the positive pole of the generator, the negative pole whereof remains grounded through wire 47, and to throw switch 61 of the local recorder circuit so that said circuit is open when the relay armature contacts with its back contact. Under such conditions our improved signaling device is capable of perfectly operating and transmitting to central station its indications of activity in the lire extinguisher systern. Assuming for example that the main wire 30 be broken, upon the rocking of the time switch attendant upon the opening of the valve 11, and the consequent shifting of the movable body of mercury, the following action takes place: The opening of the supervisory branch of the main line circuit at contacts 36, 37, produces no effect, as, obviously, under the conditions adverted to no current is normally in flow through the system. The closing of the contacts of the chamber 20 of the time switch, however, establishes a circuit for the generator, by wires 30, 49, switch blade 6 and wire 43 to point 31, and through parallel paths on one hand comprising coil d wire. 39 and wire 38 t0 the mercury, and on the other hand including wire 42,.coils d", d, wire 41, contact and pen 0, 6, wire 32, pen and contact 6 0, wire 33, magnet coil d and wires 34, 35 to the mercury. Here the parallel paths oin and circuit is completed through wire 51, pen x, wheel :0, the box frame and grounded wires 50 and 47 to the negative terminal of the gen erator,

It will be seen that while current flows through'all of the coils of the balanced magnet D the direction of current flow through each coil except d is opposite to that in which it flows under normal conditions of the circuit when the magnet is balanced. An unbalanced condition, therefore, prevails in the magnet so that its armature is attracted and the transmitting instrumentalities conditioned for operation to transmit a single round.

Now as the wheels (1 a and a' start in revolution the insulated portion 11; of the wheel at breaks the ground connection of the time switch by raising the pen a from contact with the'metallic portion of the grounded wheel :0. By this operation the main line circuit is again opened so' that no current flows therethrough. N ow as the teeth of a number wheel a or a pass beneath the corresponding )en, a ground circuit connection is made by t e wires 30, 49, 43, the appropriate branch of the circuit containing the thentransmitting pen through the teeth of the wheel and. the grounded wire 50 and back to the enerator by grounded wire 4-7. Thus it will e seen that the passage of each tooth beneath a pen causes an impulse to traverse the rela F, at central station, causing the recor er 58 to register a character in the usual manner. Should the line wires 43 and 46 be broken the action of thesystem is substantially the same as just described, the pens b I) getting their connection with the 1 generator through the line wire 30, and the round connection through the grounded rame as before.

In the modification shown in Fig. 9, if the valve 11 be raised, as a result of a disturbance of the normal conditions within the chamber 10, for a time sufficient for the mercury to flow from the chamber 20 of the time switch, and thusopen or break the circuit between become unbalanced, the wheels a, b and :0 will be revolved. The pen I) and wheel a will send in a signal over the wires 30, 41, coils d and (1*, wires 42, 44 and 46 through ground to generator G. Closing of the valve 11 will restore the circuit between the points 35 and 38, thus balancing the relay 1) and again tripping the box causing a repetition of the signal over the circuit just described.

It will be apparent now that our system rovides a means for transmitting signals rom a movable member within a hermetically closed, fluid containing receptacle of a the extinguisher system without rendering said receptacle liable to leakage; provides means for the prevention of the transmission of a signal by momentary changes of condi- ';tion in the. receptacle of the extinguisher system; provides means for controlling both local and central station alarm and signal devices by a common instrumentality; pro- I vides a complete central energy system wherem the main line and parallel branch wires are under constant test; and further provides a the wires 35 and 38, the relay 1) will thus proper operation by the rupture of one of the main wires.

Other and further advantages of our system will be apparent to those skilled in the art, but it will be understood-that we do not desire to limit ourselves to the use of the specific apparatus and connections herein shown and described further than as specified in the claims.

Having thus described our invention, what we claim and desire to secure by Letters Patent of the United States, is

1. In combination with a fluid-containing receptacle of a fire extinguisher system, a diaphragm closing an openin in said receptacle, a movable part within the receptacle, a signal transmitting box without the receptacle provided with a trippin device, and connections whereby the movable part within the receptacle controls the signal box including a lever fulcrumed in the diaphragm and means for retarding the operation of the tripping device after functional movement of the part within the receptacle. Y

2. In combination, a receptacle of a fire extinguisher system, a part in said receptacle movable by variations of conditions therein, a diaphragm closing an opening in said receptacle, an electric signal transmitting hox, a controlling or supervisory circuit therefor, a time switch operatively associated with said circuit, and connections whereby said switch is controlled by the movable part' 4. In combination, a receptacle of a fire extinguisher system, a movable part within said receptacle, a diaphragn'i constituting part of the receptacle, an electric signaling device, a circuit therefor, a time switch arranged to control said circuit, and operative connections between said time switch and the part within the receptacle whereby the movements of said time switch are controlled by the part within the receptacle, said connections comprising a lever fulcrumed within the diaphragm.

5. In combination, a fluid receptacle of a fire extinguisher system, a movable part in said receptacle, arranged to be actuated bymovcment ol' the fluid, a diaphragm consti- 05 zsystem which will not be incapacitated for l tuting part of said receptacle, a signal transmitter without the receptacle, a signal responsive device, circuit connections therefor, a time switch controlling the operation of the signal transmitter, and connections whereby the movements of the switch are controlled by said movable part, Within the receptacle, said connections comprising a lever fulcrumed in the diaphragm and operatively associated with the movable part.

6. In combination, a receptacle of a fire extinguisher system, a movable part of said receptacle, a diaphragm constituting a part of said receptacle, an electric time switch arranged without the receptacle, a local alarm circuit controlled by said switch and operative connections between said switch and the moving part within the receptacle, Whercby the movable part controls the operation of the switch, said connections comprising a lever fulcrumed in the diaphragm.

7. In combination, a receptacle of a fire I extinguisher system, a movable part in said receptacle, a diaphragm constituting part of said receptacle, a time switchwithout the receptacle, a local alarm circuit controlled by said switch, a signal transmitting device controlled by said switch, a signal responsive device, circuit connections between said signal transmitter and signal responsive device, and mechanical connections between said switch and the moving part within the rece tacle whereby said switch is controlled by t e part within the receptacle,.said connections comprising a lever iulcrumed in the diaphragm. p

8. In combination, a receptacle of a fire extinguisher system, a diaphragm closing a portion of said receptacle, a movable part in said receptacle, a plural impulse electric naling device without the receptacle, and connections between said part within the receptacle and said signaling device, whereby the actuation of said device is controlled by movements of said part, comprising a lever fulcrumed in the diaphragm, extending within and without the receptacle, and a timing means for retarding the commencement of operation of the signaling device afterfunctional movement of the part within the receptacle.

9. In combination, a receptacle of a fire extinguisher system, a valve within said receptacle, a diaphra m constituting part of said receptacle, an e ectric time switch without the receptacle, an electric signaling device, circuit connections for said device controlled by said switch, and means for operatively connecting said switch with the valve within the receptacle for control by said valve, said means comprising a lever inlcrunied within the diaphragm, and extending within and Without the receptacle.

10. In combination, a receptacle of a fire .extinguisher system, a valve in said receptacle, a diaphragm constituting part of the receptacle, an electric time switch arranged without the receptacle, an electric signaling device, circuit connections for said signaling device controlled by said time switch, and means connecting said time switch with the valve for control by the valve, said means comprising a lever fulcruined in the diaphragm. and extending within and without the receptacle.

11. In combination, a receptacle of a fire extinguisher system, a valve in said receptacle, a diaphragm constituting part of said receptacle, a signal transmitter, a signal responsive device, circuit connections between said transmitter and said responsive device, a time switch controlling the operation of said transmitter, and means connecting said time switch with the valve for control thereby, said means comprisinga lever fulcru'med in the diaphragm.

12. In combination, a receptacle of a fire extinguisher system, a movable part in said receptacle, a signal transmitter, a signal responsive device at a supervisory station, circuit connections between said signal transmitter and supervisory device, including a ground connection at the supervisory station, an electro-responsive means for conditioning said signaling device for operation, a normally open ground connection for said electro responsive device adapted when closed to condition said electro responsive device to condition the transmitter for operation, a switch for closing said ground connection and means connecting said switch with the part within the receptacle for control by said part.

13. In combination, a receptacle of a fire extinguisher system, a movable part in said receptacle, a diaphragmconstituting part of said receptacle, a signal transmitter, a signal responsive device at a supervisory station, circuit connections between said signal transmitter and supervisory device, including a ground connection at the supervisory station, an electro-responsive means for conditioning said signaling device for operation, a normally open ground connection for said electro responsive device adapted when closed to condition said electro responsive device to condition the transmitter for operation, a switch for closing said ground connection, arranged without the fire extinguisher receptacle, means connecting said switch with the partwithin the receptacle for control by said part.

14. In combination, a receptacle for a fire extinguisher system, a movable part in said receptacle, a diaphragm constituting part of said receptacle, a signal transmitter, a signal responsive device at a supervisory station, circuit connections between said signal transmitter and supervisorydevice, including a ground connection at the supervisory station, an electro-responsive means for conditioning said signaling device for operation, a normally open ground connection for said electro responsive device adapted when closed to condition said electro responsive 'device to condition the transmitter for operation, a swltch for closing said ground connection, arranged without the fire extin station, a source of current supply, and cir-' euit connections grounded at the central sta tron, an electro responsive device adapted to condition said signal transmitter for opera- J tion, said eleotro-responsive device being connected to receive current from the said i central source of supply, a normally open 1 ground connection for said eleetro-responsive device adapted when made to condition. the

responsive device to condition the transmitter for operation, and means for successively making and breaking said ground connections, whereby said res onsive device is grounded to condition t e transmitter for operation and the ground then broken to condition the circuit for the transmission of signals from said transmitter.

16. In combination, a signal transmitting device having two make and break wheels, a normally contacting penand contact for each wheel, each wheel having break devices insulated therefrom and grounded break devices, the grounded break devices of one,

wheel being timed to operate simultaneously with the insulated break device of the other, and a suitable circuit including the two pens in parallel, and including a signal receiving dfvice and a grounded source of current supy. i In testimony that we claim the foregoing as our own, we al'IiX our signatures in pres: ence of two witnesses.

JAMES G. NOLEN. JOHN la. SHEPI'IERD. 1n presenceof- Foniii: BAIN, MARY F. ALLEN. 

